Hydroelectric power generator

Abstract

A hydroelectric power generator including a water wheel rotatably mounted in a watercourse about a rotation axis, electric generating means operatively connected to the water wheel for converting, when in use, the rotational energy of the water wheel into electric energy, and a support and containment structure for supporting the water wheel in a condition of partial immersion in the watercourse and maintaining the rotation axis in a substantially horizontal position. The water wheel, the means of electrical generation and the support and containment structure are configured to adjust, in relation to the flow of the watercourse, the level of the water upstream of the water wheel with respect to the level of the water downstream of the water wheel.

Description

[0001] HYDROELECTRIC POWER GENERATOR

[0002] The present invention relates to a device for generating hydroelectric power by exploiting the hydraulic currents of natural or artificial watercourses.

[0003] As is well known, hydropower is a form of renewable energy that derives from the gravitational potential energy possessed by a mass of water contained in a reservoir, natural or artificial, located at a certain altitude, or directly from the kinetic energy possessed by a watercourse overcoming small differences in height. This energy is converted into electricity through turbines connected to generators, typically consisting of alternators.

[0004] Hydroelectric power generation is a sustainable and low-carbon process, but it generally involves the construction of complementary works such as dams, reservoirs, conduits, canalizations and the like, which have the disadvantage of being very costly and of considerable environmental impact.

[0005] ITTV20100068A1 discloses a hydroelectric plant having a partially immersed balance tilting system of the horizontal axis cylindrical rotor module and an integrated conveyor for producing electricity from flowing watercourses.

[0006] A problem of such type of generator is to assure efficiency of the system according to the variations of the flow rate of the watercourse.

[0007] The aim of the present invention is to provide a hydroelectric power generator that overcomes the drawbacks of the cited prior art.

[0008] Within this aim, an object of the invention is to provide a hydroelectric power generator that allows water energy to be exploited substantially over the entire course of a watercourse, and not only in the vicinity of dam structures, with relatively little environmental impact.

[0009] A further object of the invention is to provide a flexible hydroelectric power generator that can be adapted to pre-existing situations.

[0010] A further object of the present invention is to provide a hydroelectric power generator that can be adapted to riverbeds of different sizes.

[0011] A further object of the invention is to provide a hydroelectric power generator that does not compromise the final destination of the watercourse to which it is applied. The above aim and objects, and others which will better appear hereafter, are achieved by a hydroelectric power generator as claimed in the appended claims.

[0012] Further characteristics and advantages will become better apparent from the description of a preferred, but not exclusive, embodiment of a hydroelectric power generator according to the invention, illustrated by way of non-limiting example in the accompanying drawings:

[0013] Figure 1 is a schematic perspective view of a hydroelectric power generator according to a first embodiment of the invention;

[0014] Figure 2 is a partially sectioned frontal schematic view of the device of figure 1 ;

[0015] Figure 3 is a section along line Ill-Ill of figure 2;

[0016] Figures 4 and 5 are sectional schematic perspective views of the device of figure 1 ;

[0017] Figure 6 is a schematic perspective view of a device according to a further embodiment of the invention;

[0018] Figure 7 is a cross-sectional view of the device of figure 6.

[0019] With reference to the figures, the hydroelectric power generator according to the invention is generally designated by the reference numerals 1 and 101 , according to the first and second embodiment, respectively.

[0020] The device 1 , 101 is designed for installation in a natural or artificial watercourse 50, 150, such as a river or a canal for irrigation water.

[0021] Advantageously, the device according to the invention can be part of a complex hydroelectric power generation system formed by a plurality of substantially identical or equivalent devices operatively arranged along the same watercourse.

[0022] The device 1 , 101 substantially comprises a water wheel 10, 110 rotatably mounted around a rotation axis X and configured to convert the kinetic energy of the watercourse 50, 150 into rotational mechanical energy.

[0023] The device further includes electrical generating means 20, 120, comprising for example one or more alternators or one or more dynamos coupled to the water wheel 10, 110, that convert the rotational energy of the water wheel 10, 110 into electrical energy. A support and containment structure 30, 130 supports the water wheel 10, 110 in a condition of partial immersion in the watercourse 50, 150 and maintains the axis of rotation X in a substantially horizontal position.

[0024] According to the present invention, the water wheel 10, 110, the electric generating means 20, 120, and the support and containment structure 30, 130 are configured to adjust the water level upstream of the water wheel 10, 110, in relation to the flow rate of the watercourse 50, 150, with respect to the water level downstream of the water wheel 10, 110.

[0025] In case of a low flow rate of the watercourse 50, 150, the device is capable of increasing the water level upstream of the water wheel 10, 110, also by a braking action of adapted means (not described) for adjusting the rotation speed of the water wheel 10, 110.

[0026] In this way, the device 1 , 101 is also able to exploit the gravitational potential energy of the mass of water located upstream of the water wheel 10, 110, in addition to the kinetic energy of the watercourse 50, 150, thereby making the amount of electrical energy produced more constant and regular over time.

[0027] It should be noted that throughout the description and claims, terms such as "upstream" and "downstream" refer to the direction in which the water advances towards the water wheel 10, 110.

[0028] Preferably, the water wheel 10, 110 consists of modules, substantially equal to each other, juxtaposed and joined by mechanical fastening.

[0029] Although the present description mentions only two modules, designated by the reference numerals 10a, 10b, and 110a, 110b, the skilled person in the art will readily understand that the number of modules may vary, for example depending on the size of the riverbed in which the device 1 , 101 is installed.

[0030] Modules 10a, 10b, and 110a, 110b can, for example, be made of aluminium alloy or composite material in order to lighten the weight of the hydraulic wheel 10, 110 without affecting its performance characteristics.

[0031] Preferably, each module 10a, 10b, and 110a, 110b is axially bounded by a pair of substantially circular headwalls 13a, 13b, and 113a, 113b, attached to a central shaft 11 , 111 defining the axis of rotation X of the water wheel 10, 110.

[0032] The end walls 13a, 13b, and 113a, 113b run orthogonally to the rotation axis X and preferably have a larger diameter than the central shaft 11 , 111.

[0033] Longitudinal ends of a plurality of blades 12, 112 are attached to the head walls 13a, 13b, and 113a, 113b of each module 10a, 10b, and 110a, 110b. The blades 12, 112 are supported by a frame 14, 114.

[0034] According to an embodiment of the invention, the blades 12, 112 are polygonal in shape, preferably rectangular or square, and are arranged angularly equally spaced about the axis of rotation X; this ensures the greatest possible continuity of the electrical energy collected along the axis of the water wheel 10, 110, as well as favouring a start of rotation even at low water flow speeds.

[0035] Advantageously, the blades 12, 112 are arranged spaced with respect of the central shaft 11 , 111 , so as to form a free span between an inner edge thereof and a periphery of the central shaft 11 , 111.

[0036] This free span allows water to pass when the water level, upstream of the water wheel 10, 110, exceeds a maximum acceptable level, thereby preventing the thrust acting on the blades 12, 112 and on the central shaft 11 , 111 from damaging the device 1 , 101.

[0037] Preferably, the blades 12, 112 are mutually arranged so as to be substantially tangent to an imaginary circumference concentric to the rotation axis X.

[0038] According to the illustrated example, the imaginary circumference has substantially the same radius of curvature as the central shaft 11 , 111.

[0039] Such configuration helps to allow the water flowing within a sector defined by two adjoining blades 12, 112, to completely fill an operating volume of such sector, slightly slowing down the water flow upstream of the water wheel 10, 110, resulting in a gradual and controlled raising of the level of the watercourse 50, 150.

[0040] Also, such configuration make the hydrostatic pressure, exerted by the water contained in the operative volume of the sector defined by two adjoining paddles 12, 112, to be more uniform, while the outflow of said water, downstream of the water wheel 10, 110, is faster and less turbulent. According to the present description and claims, the term "operational volume" indicates a volume actually occupied by water.

[0041] Figures 6 and 7 illustrate a second embodiment of the invention, wherein the same and / or equivalent components of the embodiment of figures 1 to 5, are indicated by the same reference numerals increased by 100.

[0042] The water wheel 110 comprises movable adjusting members 116 that allow the displacement to be varied.

[0043] More particularly, the movable adjusting members 116 are configured to move, either automatically or manually by operators, in response to different operating conditions, between two limit positions respectively corresponding to a maximum displacement of the water wheel 110, wherein the value of the operating volume of each sector defined between two adjoining blades 112 is maximum, and a minimum displacement of the water wheel 110, wherein the value of such operating volume is minimum.

[0044] The movable adjustment members 116 may consist, for example, of swinging baffles hinged to the blades 112.

[0045] Advantageously, the movable control elements 116 are operable by means of actuating elements 117, which may consist, for example, of fluid-dynamic cylinders or other adapted actuation means.

[0046] Preferably, in this second embodiment, the blades 112 are also provided with at least one movable or elastically deformable portion 115 to allow the passage of particularly hard foreign bodies, possibly present in the watercourse 150. Such foreign bodies could in fact block or even damage the water wheel 110 and, more generally, the device 101 as a whole.

[0047] Advantageously, the movable / deformable portion 115 is formed at an outer edge 112a of each blade 112.

[0048] The water wheel 10, 110 is rotatably supported by the support and containment structure 30, 130.

[0049] The support and containment structure 30, 130 preferably has a general channel shape, with a bottom wall 31 , 131 that, in use, is arranged coplanar to a bed 51 , 151 of the watercourse 50, 150.

[0050] The support and containment structure 30, 130 also has two side walls 32a, 32b, 132a, 132b extending from opposite sides of the bottom wall 31 , 131.

[0051] The central shaft 11 , 111 of the water wheel 10, 110 is rotationally constrained to the two side walls 32a, 32b, 132a, 132b, by means comprising, for example, rolling or sliding bearings.

[0052] Advantageously, a deflector element 34, 134 extends from the bottom wall 31 , 131. The deflector element 34, 134 forms a cradle 33, 133 accommodating a portion of each blade 12, 112 close to an outer edge 12a, 112a.

[0053] The cradle 33, 133 is arranged coaxially to the axis of rotation X and is delimited at the top by a face having a concave cylinder sector profile, having a radius of curvature Ri slightly greater than a maximum radius R2of the water wheel 10, 110.

[0054] In this description and claims, the term "slightly higher" is intended to indicate that the difference between the two radii RT and R2is such that the water wheel 10, 110 can be rotated without any friction or rubbing and, at the same time, a certain degree of water tightness is ensured.

[0055] Advantageously, the angular amplitude Ai of the cradle 33, 133 is greater than a maximum angular amplitude A2of each sector formed between two adjoining blades 12, 112. Thus, during rotation of the water wheel 10, 110, the water filling the sector exerts a substantially uniform hydrostatic pressure on the two adjoining blades 12, 112.

[0056] The support and containment structure 30, 130 also has a housing 35, 135 for the electrical generating means 20, 120.

[0057] The electric generating means 20, 120 are coupled to the hydraulic wheel 10, 110 by means of the interposition of power transmission means 21 , 121.

[0058] The power transmission means 21 , 121 comprise a revolution multiplier / reducer, which allows to multiply or reduce the rotation speed of the hydraulic wheel 10, 110 in order to respectively reduce or multiply the torque transmitted to the electric generation means 20, 120.

[0059] As apparent to the person skilled in the art, as an alternative embodiment of the invention, not illustrated, the coupling between the electric generating means and the water wheel is formed in a direct manner, or by means of a closed-loop transmission member, such as a belt, or a chain, for example.

[0060] Still, according to another embodiment of the invention, not illustrated, the electric generating means could be coupled to the water wheel by means of a gear transmission system comprising, in particular, a toothed wheel with a diameter of the same order of magnitude as that of the water wheel, associated with the central shaft, in such a way as to be integral in rotation. The means of electric generation may be arranged along the perimeter of this toothed wheel and may consist, for example, of dynamos equipped with pinions meshing with the same toothed wheel.

[0061] It should be noted that the internal friction of the electric generating means 20, 120 can be conveniently exploited to assist the braking action of the means for adjusting the rotation speed of the water wheel 10, 110, in order to gradually raise the water level upstream of the water wheel 10, 110.

[0062] Advantageously, the device 1 , 101 also includes adapted means for intercepting the watercourse 50, 150. These interception means are associated with the support and containment structure 30, 130 and are arranged upstream of the water wheel 10, 110.

[0063] Preferably, the above-mentioned interception means comprise at least one grid bulkhead, configured to protect the immersed parts of the water wheel 10, 110 from any foreign bodies that may be present in the watercourse 50, 150, and at least one watercourse barrier bulkhead 50, 150, operable for example when carrying out maintenance operations.

[0064] In addition, the device 1 , 101 is equipped with at least one load lifting crane, e.g. of the bridge type, associated with the support and containment structure 30, 130.

[0065] The use of the hydroelectric power generator according to the invention clearly follows from the above in structural terms.

[0066] In particular, the device 1 , 101 is partially buried between two opposite banks of the watercourse 50, 150 in order to affect the water characteristics of the watercourse as little as possible. In particular, the bottom wall 31 , 131 of the support and containment structure 30, 130 is arranged substantially coplanar to the bed 51 , 151 of the watercourse 50, 150. Once the device 1 , 101 is correctly installed, it is possible to exploit the water wheel 10, 110 to convert the kinetic energy of the water into rotational energy and use the rotational energy to rotatably drive the electric generating means 20, 120. In turn, the electrical generating means 20, 120 convert the rotational energy into electrical energy.

[0067] All of this is achieved without the need for costly and impactful hydraulic engineering works such as dams, reservoirs, conduits, channels and the like.

[0068] In fact, in the case of a low flow rate of the watercourse 50, 150, it is possible to increase the water level upstream of the water wheel 10, 110, thanks also to the braking action of the means for adjusting the speed of rotation of the water wheel 10, 110. This solution enables the device 1 , 101 to also make maximum use of the gravitational potential energy possessed by the mass of water upstream of the water wheel 10, 110, in addition to the kinetic energy possessed by the watercourse 50, 150.

[0069] It should be noted that the water wheel 10, 110 can slow down its rotation speed to almost a standstill, gradually causing the water level upstream of it to increase, even by quite a lot. In this case, the water level downstream of water wheel 10, 110 will assume a minimum value, which may even be close to zero.

[0070] Another important aspect is the fact that, as mentioned above, the generator 1 , 101 can be integrated into a more complex hydroelectric power generation system consisting of several analogue generators, positioned along the same watercourse 50, 150, even at varying distances from each other, e.g. in staggered positions.

[0071] In practice, the present invention achieves the intended scope and purpose by means of the present hydroelectric power generator that allows optimising the exploitation of water power along the entire length of a watercourse, and not only in the vicinity of dams, as is typically the case. It can also generate large amounts of clean electricity when connected to other, substantially identical devices positioned along the same watercourse, even at varying distances from each other.

[0072] The hydroelectric power generator according to the invention is flexible and easily adaptable to watercourses with different widths.

[0073] Another advantage of the device according to the invention is its low installation and operating costs. This application claims the priority of Italian Patent Application No. 102024000010177, filed on May 7, 2024, the subject matter of which is incorporated herein by reference.

Claims

CLAIMS1. A hydroelectric power generator (1 , 101) comprising a water wheel (10, 110) rotatably mounted in a water course (50, 150) about a rotation axis (X); electric generating means (20, 120) operatively connected to said water wheel (10, 110) for converting, when in use, a rotational energy of said water wheel (10, 110) into electrical energy, and a support and containment structure (30, 130) configured to support said water wheel (10, 110) in a condition of partial immersion in said watercourse (50, 150) and for maintaining said rotation axis (X) in a substantially horizontal position; said water wheel (10, 110), said electric generating means (20, 120) and said support and containment structure (30, 130) being configured to adjust, in relation to the flow rate of said watercourse (50, 150), the level of water upstream of said water wheel (10, 110) with respect to the level of water downstream of said water wheel (10, 110); said generator being characterized in that it comprises means for adjusting the rotation speed of said water wheel (10, 110) in relation to the flow rate of said water course (50, 150).

2. The generator according to claim 1 , characterized in that said water wheel (10, 110) comprises a central shaft (11 , 111 ) forming said rotation axis (X), and a plurality of blades (12, 112) connected to said central shaft (11 , 111); said blades being mutually arranged and equally angularly spaced about said axis of rotation (X) and being substantially tangent to a circumference concentric to said rotation axis (X).

3. The generator according to one or more of the preceding claims, characterized in that said blades (112) comprise at least one portion (115) movable or elastically deformable to allow the passage of foreign bodies that may be present in said watercourse (150), said movable / deformable portion (115) being defined in proximity to an outer edge (112a) of each of said paddles (112).

4. The generator according to one or more of the preceding claims, characterized in that said water wheel (10, 110) comprises one or more modules (10a, 10b, 110a, 110b), substantially equal to each other, juxtaposed and joined by means of mechanical fastening; each of said modules (10a, 10b, 110a, 110b) comprising two substantially circular head walls (13a, 13b, 113a, 113b), fixed to said central shaft (11 , 111); said head walls (13a, 13b, 113a, 113b) being orthogonal to said axis rotation (X) and havinga diameter greater than the diameter of said central shaft (11 , 111 ); the longitudinal ends of said blades (12, 112) being integral with said head walls (13a, 13b, 113a, 113b).

5. The generator according to one or more of the preceding claims, characterized in that said water wheel (10, 110) comprises a support frame (14, 114) for said blades (12, 112); said frame (14, 114) being enclosed between said head walls (13a, 13b, 113a, 113b).

6. The generator according to one or more of the preceding claims, characterized in that said water wheel (110) comprises movable adjustment elements (116) adapted to move, in response to operating conditions of said generator (101 ), between two limit positions corresponding respectively to a maximum displacement of said water wheel (110), wherein the value of an operating volume of each sector defined between two adjacent blades (112) is maximum, and a minimum displacement of said water wheel (110), wherein the value of said operating volume is minimum.

7. The generator according to one or more of the preceding claims, characterized in that said water wheel (110) comprises control elements (117) of the movement of said movable adjustment elements (116).

8. The generator according to one or more of the preceding claims, characterized in that said support and containment structure (30, 130) comprises a bottom wall (31 , 131 ) configured to be arranged coplanar to a bed (51 , 151) of said watercourse (50, 150), and two side walls (32a, 32b, 132a, 132b) protruding from opposite sides of said bottom wall (31 , 131); said central shaft (11 , 111) being rotatably constrained to said two side walls (32a, 32b, 132a, 132b) about said rotation axis (X).

9. The generator according to one or more of the preceding claims, characterized in that said bottom wall (31 , 131) comprises at least one cradle (33, 133) for receiving a portion of each of said blades (12, 112) close to an outer edge (12a, 112a); said cradle (33, 133) being coaxially disposed with said rotation axis (X) and being delimited on the top by a face having a concave profile in the shape of a cylinder sector, having a radius of curvature (Ri) slightly greater than a maximum radius (R2) of said water wheel (10, 110) and having an angular amplitude (Ai) greater than a maximum angular amplitude10. The generator according to one or more of the preceding claims, characterized in that said support and containment structure (30, 130) comprises a housing (35, 135) for said electrical generating means (20, 120).11 . Generator according to one or more of the preceding claims, characterized in that it comprises power transmission means (21 , 121 ) between said water wheel (10,110) and said electrical generation means (20, 120).

12. The generator according to one or more of the preceding claims, characterized in that said power transmission means (21 , 121 ) comprise at least one toothed wheel, having a diameter of the order of magnitude of the diameter of said water wheel (10, 110); said toothed wheel being rotationally integral with said central shaft (11 ,111 ) and engaging with at least one pinion associated with said power generation means (20, 120).

13. The generator according to one or more of the preceding claims, characterized in that it comprises means for intercepting said watercourse (50, 150), associated with said support and containment structure (30, 130) and arranged upstream of said water wheel (10, 110); said interception means comprising at least one grid bulkhead for protecting immersed parts of said water wheel (10, 110) from foreign bodies that may be present in said watercourse (50, 150), and at least one barrier bulkhead of said watercourse (50, 150).

14. The generator according to one or more of the preceding claims, characterized in that it comprises at least one load lifting crane associated with said support and containment structure (30, 130).

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